Refuse, litter (7)
I believe the answer is:
rubbish
This clue is a double definition.
'refuse' is the first definition.
(refuse can mean rubbish or waste)
'litter' is the second definition.
(I know that litter can be written as rubbish)
(Other definitions for rubbish that I've seen before include "Waste matter" , "Codswallop or trash" , "Worthless material or nonsensical talk" , "Nonsense or refuse" , "Nonsense; very bad" .)